The study continues to evaluate immediate and long-term effects of continuous glucose feedings on the metabolic and hormonal state, and physical growth and development of patients with type one glycogen storage disease. The broad goals of this study are to test the hypothesis that optimal continuous glucose therapy of type 1 glycogen storage disease (GSD-1) provided by an appropriate diet supplemented with a regimen of intermittent feedings of uncooked cornstarch can promote normal physical growth and development, and will prevent or delay renal and hepatic complications of the disease. The study has previously shown that continuous glucose treatment improves growth in previously untreated GSD-1 patients, but catch-up growth was incomplete and predicted final adult height was significantly less than target height. The study has shown that night feeds of uncooked cornstarch does not impair nocturnal GH secretion. Careful long-term follow-up of this cohort of GSD-1 subjects, who were diagnosed early in life and have been intensively treated from an early age, will give the investigators the opportunity to test the hypothesis that maintenance of near normal biochemical control throughout childhood and adolescence results in normal growth and attainment of target or mid-parental height. The study to date, has preliminary data which suggests that microalbunimuria, a sign of early renal glomerular damage, is significantly associated with delays in starting glucose therapy and with chronic hyperlactatemia. There is reason to hope that optimal continuous glucose therapy from infancy with maintenance of near to normal concentrations of blood lactate may delay or prevent renal dysfunction in GSD-1. All subjects will continue to be closely monitored for early signs of renal dysfunction (microalbuminuria, hypertension).